Quiet Aftermarket Exhausts?

[long post but specific response for a particular member ]

wynne - just bought a good used leo vince lv one evolution II
which comes with three options for reducing flow thru the cannister
[mine black/carbon - black bike] being; a cup shaped reducer that fits
[nicely] into the front of the cannister, solid, well made, which also
has five holes in it [imagine a mug with 5 holes in the bottom]
which amount to something like a bit less than half the flow-thru..
nice and solid, appears capable of easily holding say stainless
wire wool [pot scourers etc] if one wired some to the inside
of this 'db killer' which would further reduce flow-thru..
also has two inserts for the rear end, both fit well and snugly
one smaller/shorter than the other, potentially noisier..
has a nice solid well designed bolt with rubber plug securing it..

states; "E-marked LeoVince exhaust systems have been granted
EEC approval. They are manufactured in accordance with European
directive 97.24CEm and are marked with the appropriate homologation
number which is stamped into the product.
Customers who purchase an e-marked LeoVince product and fit it to their
machine have the following rights;
1 The machine can be used freely on the road, not only in their own national
territory, but throughout the EC. In particular, if they are subject to an
inspection by the nominated government department, and they show the
homologation certificate which is enclosed, this is sufficient to prove the
suitability of the exhaust for the vehicle to which it is fitted.
2 The rider has the right to fit this exhaust with no modification
to the registration document of the vehicle. In Italy [etc]"

also; "ITEM - No 8558 REF. 8559
TO FIT - HONDA CBR 250 R ie
ORIGINAL NO MC41 - MC41 1 1
TYPE APPROVAL - e13 0430 (9)
IN CONFORMITY WITH - EC DIRECTIVE 97/24"

one page is a copy of a statement, stamped and signed etc
to the effect that the silencer complies with the directive etc of
"Chapter 9 regarding permissible sound level and exhaust system"

so it seems youre sweet with officialdom at least with this slip on..
when i install it both the cup shape inlet reducer and larger insert
will be used.. from various you tube sound demos of the same
exhaust it doesnt seem offensive and has a nice enough tone
at idle and rev'd to around suburban riding revs..
at any rate, theres always the option of extra flow reduction
if that seems necessary [good wire wool seems an easy option]..

even if it means slightly altering my typical riding style etc
when in suburbia or sensitive areas i dont see a problem..
my last honda 750/4 [K6] had a four into one system
which could make a strong 'howling' sound, when let go,
but for suburban riding it was more a soft moaning..
in other words you can ride it, loud or 'not offensive'..

for interest, the booklet lists the stock exhaust weight
8,438g [18.6lb] compared to the lv cannister 1,690g
+ link pipe 480g [1.06lb] total 2,170 [4.78lblb]
for a saving of 6,268g or 13.82lb [!]

from egs on you tube you can vary the angle of the cannister
and how close you bring it into the bike, by varying the curve
alignments from fitting point to the stock header pipe, plus
whether you mount the cannister retaining strap to the front
or rear of the mounting bracket under the right passenger peg..
i like the smoother direct angle which matches the underside
lines of the rear section under the seat to tail, also prefer
the tighter mounting with the strap to rear of bracket..

but we'll see when its installed [not immediately]..

this carbon slip on looks and feels well made..
everything fits snugly, its oval shaped, end cap
is flat black, center carbon a sort of textile striping
of dark grey and black wavy lines, slight sheen..
front end and link pipe look like qualtity ss..

being somewhat of a tight-arse i couldnt justify
spending $4-500aust on a slip on, so when this one
came up from a forum member for a reasonable price
and in excellent condition, and seemingly quiet enough
or able to be made quieter, i bit the bullet

it will doubtless look nice on all black 'black beauty'
not just for the matching blacks but for its general
quality look, tightness and appearance as if what
the engineers/designers of the bike would have
designed, if not constrained by california etc
emissions laws..

good luck with your own system mate,
i heartily recommend the lv one evo II
carbon slip on if thats your direction

update on lv evoII slip-on, two weeks and already
notice its become quieter, well, to be more accurate
noticed ive adapted to it in general riding style
as she sounds like a motorcycle not a lawnmower
now which is ongoing feedback as to what the engine
- ie, my input to it via the throttle - is doing..

small changes include less throttle in rev matching
when downshifting.. short sharpish blipping gives
feedback of 'not so much needed'..
noticed now not extending into rev range so far
while progressing thru gears in no hurry situations..
ie, now have less tendency to load the motor
and for a shorter time per gear..
theres a general minimal but noticeable
throttle use which doesnt effetively change
how i ride over the same routes but could be
described as 'smoother', perhaps..

this was obvious when taking her out for her
first test runs with the new lv slip on installed,
but instead of just riding and listening
ive noticed myself making small changes
to lessen the bark of loaded throttling..

still let her go a bit now and then
to get a feel for any changes in engine
performance etc, when there is more of
an obvious motorcycle sound..
performance wise, engine seems to 'like'
the lv slip-on.. take off is particularly clean
and smooth, incl rolling thru/exiting turns..
without dyno, she feels a touch stronger
around maximum torque range [5.5-7.5 say]
without any obvious power hit higher up..
seems to maintain a smooth flow of power
from that nice higher torque range..

taking off at predawn in my apartment area
[downhill] she has a nice not too loud low toned
idle once settle to 1500, then its easy to ease away
with soft throttle at quite acceptable speed etc
without making enemies of the neighbours..

so however a good slip-on with reducers
sounds at first doesnt need to be all its
capable of after even a couple of weeks
riding and adjusting to its different
sound and slightly different power etc..

this is meant to be somewhat reassuring
for members with some concern for
potential noise making/neighbours etc..

ps, yesterday riding past the police stn/courthouse
group of 5 or 6 uniformed police on my side footpath
didnt even look up as we eased bye [4th probably]